Flashcards
Sem título
Flashcards do conjunto (22)
- 1What effect does the waste energy from a power station have on the surroundings?the temperature increases making it more warm.
- 2Why is a CHP station more efficient than a traditional coal-burning power stationThe CHP station is more efficient than the traditional coal burning power station because some of the energy that would be wasted is used usefully to heat homes
- 3What is the National Grid?A system of cables and transformers.
- 4Give one reason why using electricity locally is more efficient than using it through the national gridThe Effiency of the CHP station increases by 7% when used locally because there is less energy lost in shorter cables.
- 5Why does the mirror get misty when a person showers?When a person uses the shower the mirror starts to get misty because water evaporates and because the mirror surface is cooler than the damp air when the particles hit the mirror they lose energy causing condensation on the mirror.
- 6why is it that when a person has a shower the heated mirror stays clearthe mirror is heated which makes it warm so the rate of condensation is decreased
- 7The oscillations producing a light wave are .................................................................. to the direction of the energy transfer by the light wave.Perpendicular
- 8Describe how switching the desk lamp on and off shows that light waves transfer energy.As the light is switched off there is either no rotation or slow rotation but as the light is switched on there is a faster rotation
- 9What is a virtual image?where rays of light seem to come from it but do not pass through it.
- 10Why does having a plastic cap. double walled glass container, vacuum and silvered surfaces help keep the liquid hot?plastic is poor conductor so it reduces the rate of evaporation, conduction and convection because it stops the convection currents forming at the top and it stops the particles evaporating to the air because they can not mover. Glass is a poor conducter reducing energy transfer by conduction. both conduction and convection need a medium so the cvacuum stops energy transfer by convection and conduction. the silver surfaces reflect infrared radiation because they are poor emitters of infrared radiation reucing energy transfer by radiation.
- 11How does the size of the ears help to keep the fox warm in a cold environment?their ears have a small surface radiation therefore reducing energy transferred from the fox.
- 12How is energy is transferred by the process of convection from the hot water at the bottom of the tank to the cooler water at the top.the molecules gain energy and the molecules move apart causing the water to become less dense and the hot water to rise through the tank.
- 13what is the main way of transferring energy through a copper wall of the water tank.Conduction.
- 14The temperature of the water falls at the fastest rate just after the heater switches off.there is a huge temperature difference between the air and the water so the transfer of hot energy from the water is faster.
- 15Calculate the mass of the water in a tank with a 8 degrees difference, 4032 kj and a specific heat capacity of 4200J/kgm x 8 x 4200 = 4032,000 = 4023, 000/8/4200 = 120
- 16explain why fitting an insulating jacket to a hot water tank saves money.the water stays hot for longer so the heater is on for less time which means that the payback time is short so lower energy bills.
- 17Explain one effect that burning fossil fuels has on the environment.it produces greenhouse gases that contribute to global warming.
- 18Give one way the effect on the environment could be reduced.removing the sulfur before burning the fossil fuel.
- 19What is the importance of the short start-up time?it starts generating in a short time.
- 20Give one other advantage of a pumped storage hydroelectric power station.it can store energy for later use.
- 21Suggest one reason why some people think wind turbines the increase will cause big fluctuations in the electricity supplywind is an unreliable energy source.
- 22suggest one reason why lighting in homes have decreased.more people are becoming environmentally aware.
Informações
- Descrição
- FlashCards sobre Sem título, criado por Praise Famuyiwa em 01-05-2015.
- Criado por
- Praise Famuyiwa
- Visualizações
- 0
- Avaliação